Microchannel plate electron multiplier devices provide exceptional electron amplification but are generally limited in application on account of their delicate glass structure. The device basically consists of a honeycomb configuration of continuous pores through a thin glass plate. Secondary emissive properties are imparted to the walls either by chemically treating the glass walls of the pores or coating an emissive layer thereon. Electrons transporting through the pores subsequently generate large numbers of free electrons by multiple collisions with the electron emissive internal pore surface.
Since each pore corresponds to an individual hollow glass fiber, the entire structural properties of the microchannel plate depends upon the mutual cohesion between each and every individual fiber in the plate. Their use therefore has heretofore been limited to applications where microchannel plates having solid square or solid circular geometries can be employed since structural support is then uniform in all directions of the solid geometry.
One important application which requires the small pore geometry and high electron amplification of microchannel plate electron multipliers is in focal plane mass spectrometers. In this application the microchannel plate electron multiplier serves as an ion-electron converter providing high spectrometer sensitivity and good mass resolution. The effective focal plane in most focal plane mass spectrometers, however, is in the order of 30-40 cm., whereas the largest microchannel plates currently available are only 10 cm. in diameter. Combining three or more 10 cm. long rectangular areas cut from microchannel plates together produces an operable array which is, however, inherently weak structrually and which adversely results in end-to-end variation in electron amplification between the individual composite sections.
The purpose of this invention therefore is to provide a structurally sound strip microchannel electron multiplier array having uniform electron amplification properties from end-to-end together with an overall geometry compatible with the mass spectrometer focal plane.